This application claims the benefit of co-pending German Patent Application No. 199 18 740.1-23 entitled xe2x80x9cPrxc3xa4gekette zur Herstellung von Bonbonsxe2x80x9d filed on Apr. 24, 1999.
The present invention generally relates to a chain die assembly and to a die apparatus. Such chain die assemblies are used in die apparatuses with which candy is separated from a continuous rope of candy mass to be formed in die chambers. The chain die assembly as a substantial element of the die apparatus may be used for the production of hard candy and chewy candy. It may be also used for the production of filled candy.
Chain die assemblies generally include an endless upper chain and an endless lower chain cooperating to form die chambers for the candy to be produced. The die chambers are limited by chain links of the upper chain and by chain links of the lower chain. Additionally, there are dies right and left of a common longitudinal center plane of the chain die assembly and of the die apparatus. The dies also limit the die chambers. The dies are arranged either at the upper chain or at the lower chain. Especially, the dies are only arranged at the upper chain to make it easier to watch their operation and their correct function. The present invention relates to the portion of the chain die assembly carrying the dies. As already described above, this portion may either be the upper chain or the lower chain. Preferably, the present invention relates to the upper chain of the chain die assembly.
A chain die assembly is known from European Patent No. EP 0 352 233 B1. The die apparatus includes a frame at which the endless upper chain and the endless lower chain are driven and guided by horizontally arranged drive shafts and deflecting shafts. The upper chain carrying the dies includes two different kinds of chain links being alternately arranged. The first kind of chain links includes inward cheeks, meaning cheeks being located at a comparatively small distance with respect to the vertical longitudinal center plane of the die apparatus and of the chain die assembly. The other kind of chain links includes outward cheeks having a greater distance between each another, and surrounding the inward cheeks of the corresponding adjacent chain links. Each chain link of both kinds includes a cutting edge being arranged approximately in the middle region of each chain link and extending transverse to the running direction of the chain die assembly, and consequently, transverse to the vertical longitudinal center plane. A quarter of a hollow impression connects to the cutting edge of each chain link to the front and to the rear. Four of these quarter impressions define the cross section of the die chamber, each of these cross sections of a die chamber being formed by two adjacent chain links of the upper chain and two adjacent chain links of the lower chain. Guiding housings are arranged right and left of the longitudinal center plane in a mirror-symmetric design and arrangement. The guiding housings have a substantially U-shape design. A die is movably guided in each guiding housing right and left of the common longitudinal center plane of the chain die assembly. The dies are arranged to be movable in a perpendicular direction with respect to the vertical longitudinal center plane. Each die includes a shank being movably supported in two legs of the corresponding guiding housing having corresponding openings. Die heads are formed at the ends of the die facing in an inward direction. The die heads in combination with the chain links limit the corresponding die chamber. Rollers are arranged at the ends of each shank of each die facing in an outward direction such that the axial movement of the die into the closed position is realized by guiding bars being located at the die apparatus. The dies are actuated under prevailing roll friction. Protrusions extending in a radial direction are anchored in the shanks of the dies. The protrusions cooperate with other guiding bars under prevailing sliding friction to open the die chamber. Each guiding housing of the upper chain is pivotally connected to the chain links by two adjacent shafts. There also is a pivotal connection between the shaft and the guiding housing. Finally, each guiding housing is pivotally connected to the chain link by an adjacent shaft. Such an upper chain includes a number of chain links to which the same number of shafts and twice the number of guiding housings and twice the number of dies are allocated. Due to the great number of pivotal connections, the dies are guided with a comparatively great backlash. The backlash of each of the pivotal connections adds up to a certain total backlash. The first backlash, clearance or play is determined by a pivotal connection between the shank of the die and the guiding housing. In addition, there is the backlash between the guiding housing and the shaft. The third backlash is defined by the pivotal connection between the shaft and the chain link. Consequently, the dies with their axes are supported and movable with respect to the die chambers only with a limited precision. The limited precision and exactness results in the candy mass and the finished product being squeezed. Additionally, there is wear and tear due to the great number of pivotal connections during the rotation of the chain die assembly. The wear and tear has a negative effect on the exactness of the guidance and on the support of the dies. Such a chain die assembly has a certain limited durability or lifetime. When the wear and tear does exceed a certain value, the dimensional accuracy of the candy to be produced decreases, and the portions of the candy that are squeezed are increased to reach an extent which is no longer tolerable. The above described disadvantageous backlash in the prior art not only relates to the support and the guiding of the dies with respect to one another, but additionally, it relates to the pivotal arrangement of the chain links. Each chain link is pivotally supported at two adjacent shafts by a total number of four joints. As with all pivotal connections, the joints require backlash being increased by wear and tear. These numerous but necessary backlashes have a negative effect on the preciseness of the die operation, they result in wear and tear occurring at each pivotal connection, and they reduce the output of the chain die assembly and its lifetime. The above described wear and tear is especially important since the above described pivotal connections are designed as joints being subject to sliding friction without lubricant being used. Additionally, during production powdery sugar components cannot be prevented from entering between the surfaces. Consequently, the powdery sugar components have a substantial abrasive effect also decreasing the durability of the chain die assembly. The known chain die assembly has a strongly limited durability and lifetime, and it may only be operated at a strongly limited velocity with which the chain die assembly circulates. Thus, the power and the output of such a known die apparatus is strongly limited.
It is also known in the art to reduce the number of guiding housings compared to the number of chain links and to the number of shafts by 50 percent such that two adjacent shafts engage one and the same guiding housing. In other words, each guiding housing carries two dies. Consequently, the total number of pivotal connections is reduced. Nevertheless, the reduction does not have an influence on the exactness of the guidance of the dies at the die chambers since the two dies being arranged at one guiding housing work in two adjacent and separate die chambers. The exactness of the reproducibility with which candy is produced is not improved. The great number of joints results in the negative effect of the chain die assembly being lengthened during operation.
Briefly described, the present invention provides a chain die assembly for producing candy. More particularly, the present invention provides a chain die assembly for producing candy including a plurality of first chain links each including a cutting edge, a plurality of second chain links each including a cutting edge and a common longitudinal center plane. A plurality of guiding housings is arranged right and left of the longitudinal center plane, and they each carry at least one die. A plurality of shafts each connects one of the first chain links to one of the second chain links and to the guiding housings. The second chain links each are fixedly connected to at least one of the guiding housings to be free from backlash and to be unrotatable with respect to the guiding housing.
The present invention is based on the concept of reducing the number of pivotal connections in the chain die assembly to reduce wear and tear, and to improve the exactness with which candy is produced. At least every other chain link and a corresponding shaft and a corresponding guiding housing together form a fixed unit being free from backlash. The above mentioned elements are not pivotable with respect to one another. The above mentioned elements form a unit which only moves with respect to other parts not being part of the fixed unit. The elements may also be made of one piece. For reasons of an easier production and an improved mountability and demountability, the chain link, the corresponding shaft and the corresponding guiding housing are mounted in a way that there is no friction and no wear and tear between these elements. In the prior art chain die assemblies, a first pivotal connection is arranged between the chain link and the shaft, and a second pivotal connection is arranged between the shaft and the guiding housing. The novel chain die assembly does not include these two pivotal connections. The dies still have to be movably guided in the guiding housings. The dies are guided with respect to the chain links with a substantially increased exactness since the novel chain die assembly does not include the above described two pivotal connections. The candy is prevented from being squeezed. The candies attain the desired dimensions. The durability and the lifetime of the chain die assembly is increased due to the reduction of joints including backlash. The wear and tear is reduced. This also results in noise being reduced during production. With the novel chain die assembly, it is possible to attain working velocities of the chain die assembly up to approximately 200 meters per minute. The limit for the working velocity of the chain die assembly has been approximately 100 to 120 meters per minute in the prior art. Another advantage of the novel chain die assembly compared to chain die assemblies known in the prior art is that it is not necessary to arrange distance sleeves between the chain links having the outward cheeks and the guiding housing. The reason for this fact is that the above mentioned elements are combined to form one fixed unit. With this arrangement, not only the weight of the assembly is reduced, but the chain die assembly also has a very compact design. The present invention is also applicable to chain die assemblies in which the number of guiding housings is twice as great as the number of chain links. This means that one die is slidingly and movably supported in one guiding housing. The present invention is also applicable to chain die assemblies in which the number of guiding housings and the number of chain links is identical. Such an arrangement means that two dies of adjacent die chambers are movably supported in one common guiding housing. The arrangement of the two dies of one die chamber right and left of the vertical longitudinal center plane of the chain die assembly with respect to one another is improved due to the combination of the above mentioned elements as one fixed unit. The chain links having outward cheeks are not movable with respect to the shafts. Only the chain links having inward cheeks are pivotable with respect to the shafts. It is to be understood that the angles to be pivoted through and the relative movement is increased during the deflection of the chain die assembly. Nevertheless, wear and tear does not increase proportionally with respect to this angle. In the first place it is the break away force in the pivotal connections to be overcome during each deflection that has a negative effect on the output and that increases friction.
It is especially preferred if the two guiding housings right and left of the common longitudinal center plane of the chain links are fixedly connected with one another by a corresponding shaft. In this way, a unit being stiff in a transverse direction with respect to the longitudinal center plane is provided. The unit continuously extends over the width of the chain die assembly such that a symmetric design with respect to the longitudinal center plane is achieved. It is known in the prior art to use shafts which are produced without a determined permissible variation or tolerance. Such a tolerance is not necessary to form the numerous joints. It is clear that different backlashes result in the joints in the prior art. These backlashes in the prior art have a negative effect on the output and the power of the chain die assembly, and they reduce the durability and the lifetime of the chain die assembly. The novel chain die assembly cooperates with shafts the diameter of which has been produced with a predetermined certain permissible variation or tolerance. These allowable tolerances are determined in coordination with the bores being located in the chain links and in the guiding housings.
In an especially preferred embodiment of the present invention every other chain link is connected to two corresponding shafts and to one common guiding housing carrying two dies to form a fixed unit being free from backlash. The guiding housings are flanged to the cheeks of the chain links having outward cheeks. The two guiding housings right and left of the longitudinal center plane each serve to support two dies. They are interconnected by two shafts to be adjusted with respect to one another. The above described preferred arrangement improves the exactness of the die process and consequently the dimensional accuracy of the candy.
There is a number of possibilities for the assembly of the above mentioned elements to form a fixed unit being free from backlash. It is especially easy to realize such a combination of the elements by connecting the chain link, the shafts and the guiding housing to form an unmovable but demountable unit by using interference fits or press fits. The fixed and unmovable unit has to be detachable, for example, to assemble and to disassemble the chain die assembly. It may be also necessary to replace certain elements. In case of an arrangement using interference fits, the outer diameter of the shafts are overmeasured compared to the diameter of the bores in the elements to be combined to form a fixed unit. It is possible to assemble the elements by applying pressure in a direction perpendicular to the vertical longitudinal center plane.
Another advantageous embodiment of the present invention is an arrangement in which the guiding housing, on the one hand, and the chain link, on the other hand, each include two bores being located on both sides right and left of the common longitudinal center plane. Two adjacent shafts extend through the bores. The axes of the two bores being located in the chain link are displaced with respect to the axes of the two bores being located in the guiding housing in a way that friction occurs during assembly of the unit. This is true for each side right and left of the longitudinal center plane. With this arrangement, the two shafts being located in the bores of the guiding housing and in the bores of the chain links having the outward cheeks are clamped with respect to one another. The attainable frictional connection securing the fixed unit depends on to what extent the axes are dislocated with respect to one another. In this embodiment of the present invention, the guiding housing and the chain link on both sides right and left of the common longitudinal center plane may each be connected to an additional screw. These screws have several functions. They serve to facilitate the assembly of the elements by the guiding housing approaching the outward cheeks due to the screw. This is especially advantageous in the last portion of the movement during which the dislocation of the axes resulting in frictional engagement makes it hard to overcome the clamping force. Additionally, the screw secures the flange connection between the guiding housing and the outward cheek of the corresponding chain link such that the guiding housing cannot move with respect to the shaft in an outward direction, even during operation of the chain die assembly and occurring vibrations and impact shocks.
Only the chain links having outward cheeks are connected to the guiding housings and to the two shafts in a way to form a fixed unit. The chain links having inward cheeks are movable with respect to the shafts. This means that these chain links are pivotally connected to the shafts. In this way, two adjacent chain links as seen in the direction of main extension of the chain die assembly are movable with respect to one another, as it is required for a chain. Only one kind of chain links is pivotally connected to a shaft, whereas it is known in the prior art to pivotally connect all chain links with respect to the shaft.
It is possible to design the one kind of chain links in a way that they have inward cheeks being wider than the outward cheeks of the other kind of chain links. Since the pivotal connection is only realized for one kind of chain links having inward cheeks, the width of the cheeks may be increased to reduce the surface pressure. Such a design also has a positive effect on the durability of the chain die assembly. The one kind of chain links having inward cheeks is pivotally connected to two adjacent shafts.
It is further possible that the two adjacent shafts, in addition to their pivotal connection by the one kind of chain links, are connected to the inward cheeks by joint bars. The joint bars are arranged parallel to the chain links having inward cheeks and in the outer region of the guiding housing. Such an arrangement is especially advantageous to increase the lifetime and the durability of the chain die assembly. The joint bars are an addition to the one kind of chain links having inward cheeks in a way that the adjacent guiding housings right and left of the longitudinal center plane are pivotally connected on a broad basis.
Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and the detailed description. It is intended that all such additional features and advantages be included herein within the scope of the present invention, as defined by the claims.